This invention relates generally to fluid pumps. More specifically, this invention relates to an improved electromagnetic fluid pump for pumping a fluid such as air for use, for example, in the aeration of water in an aquarium.
Fluid pumps in general are well known in the art and typically comprise a driven pump element for drawing a desired fluid through a pump inlet into an internal pumping chamber, and for expelling the fluid under pressure from the pumping chamber through a pump outlet. Such fluid pumps are provided in a wide variety of sizes, shapes, and constructions, and they are used for pumping a virtually infinite variety of liquid and gaseous fluids, such as water, air, and the like.
In some environments, it is desirable to provide a relatively simple and inexpensive fluid pump for pumping a fluid such as air at a relatively low pressure and flow rate. One such environment comprises, for example, an aquarium wherein it is necessary to pump air into aquarium water to aerate the water to sustain aquatic life. However, since the aquarium typically is maintained in a home or apartment by an individual such as a hobbyist, it is highly desirable for the pump to be designed for quiet operation and relatively long life. Moreover, in the event of pump failure, it is further desirable for the pump to be quickly, easily, and inexpensively repairable, even by the owner.
In the prior art, a wide variety of fluid pumps have been designed for use in an aquarium environmment. Many such fluid pumps have comprised so-called diaphragm pumps wherein a flexible diaphragm defines one wall of an internal pumping chamber, and this diaphragm is reciprocated by a direct mechanical drive to draw air into the pumping chamber and then to expel the air from the chamber. See, for example, U.S. Pat. No. 4,086,036. However, these direct drive diaphragm pumps are typically relatively complex and expensive in construction, and they include a number of moving mechanical components which sometimes are relatively noisy in operation. Moreover, these moving mechanical components are susceptible to periodic failure, and they are not easily or inexpensively repaired or replaced.
Other fluid pumps for use in an aquarium environment have been proposed in the form of diaphragm pumps including a reciprocating diaphragm driven indirectly by an electromagnet. In some of these pumps, the diaphragm is connected to a pivot arm which is mechanically reciprocated by an electromagnet, such as those shown and described in U.S. Pat. Nos. 3,671,151; 4,154,559; and 4,170,439. In other pumps, polarized ceramic diaphragms are reciprocated by an electromagnet, such as that shown and described in U.S. Pat. No. 3,029,743. Alternately, a flexible diaphragm is provided with a metal armature which is reciprocated by an electromagnet to operate relatively complex valving components, such as that shown and described in U.S. Pat. No. 2,942,772. However, in all of these pump arrangements, the moving mechanical components tend to be relatively noisy in operation and are subject to periodic failure. In the event of failure, the components are not easily or inexpensively repaired or replaced by the individual.
A primary aspect of the present invention is to provide an improved fluid pump which is of relatively inexpensive and simplified construction, which is designed for long life and quiet operation, and which is easily and inexpensively repaired in the event of pump failure.